Amusement devices such as the conventional swing and such as the roundabout, carousel or merry-go-round have long provided entertainment for both children and adults by transporting them in a back and forth and in a revolving circular pattern, respectively. Amusement devices of this type have been designed to be used freely by one or a few occupants, and are found, for example, in school yards, public parks, and home play yards. In fact, many of the smaller units have been designed to be propelled by the riders.
With certain merry-go-rounds, for example, the riders may push or pull the revolving portion of the merry-go-round, until considerable speed is attained, then leap on the ride until the kinetic energy is dissipated. Other merry-go-rounds have been designed wherein the structure for supporting the revolving load has its axis of rotation offset from the vertical so that the plane of rotation is offset from the horizontal. Such user operated merry-go-rounds are sustained in motion to a large extent by the occupants, while seated upon the device, supplying the necessary energy to move the merry-go-round in an orbital path. Examples of these inclined, merry-go-round style amusement devices are disclosed by Eckberg in U.S. Pat. No. 1,670,882; by Walker in U.S. Pat. No. 2,841,395; by Willard in U.S. Pat. No. 3,439,914; and by Halaj in U.S. Pat. No. 3,462,140.
Another type of occupant propelled amusement device is the swing. Simple swings have been used for uncounted centuries and are particularly beloved by children. The best known style of swing comprises a seat suspended by at least one flexible supporting member depending from a stationary cross member. In operation, the user simply supplies energy to move the swing forwardly and backwardly by thrusting his or her legs forwardly and then retracting them thereby defining a pumping action generally recognized as a conventional manner for inducing movement in such a swing. There are, however, other types of swings each having a different style of movement. Examples of other styles of swings are disclosed by Guihan in U.S. Pat. No. 3,127,169; by Morrow in U.S. Pat. No. 3,186,711; by Bourne in U.S. Pat. No. 3,858,871; by Potyondy in U.S. Pat. No. 4,036,489; and by Lelong in U.S. Pat. No. 4,046,375.